1. Field of the Invention
The present invention relates to an image-bearing member comprising a support material, at least part of which comprises a paper layer capable of bearing images formed by a thermofusible or a heat-softening ink, which image-bearing member can be recycled, and a method for recycling the above-mentioned image-bearing member.
2. Discussion of Background
Because of recent rapid development of office automation, a large quantity of papers for printers and copying machines has been used and consumed. This has caused the problems of the environmental disruption of the earth due to deforestation.
Conventionally, in order to recycle papers of this kind, printed ink is removed from the paper, and the ink-free paper is crushed and paper is made therefrom again. This has been an only method of recycling this kind of paper materials.
However, recently a method for recycling used copy papers by cleaning printed images off the surface of the copy paper has been developed, and examples of such a recycling method have been described, for instance, in the following references:
(1) Japanese Laid-Open Patent Application 4-67043:
There is proposed a sheet-shaped image-bearing member for supporting images thereon. This image-bearing member can be reused by treating one side of the sheet to make releasable, and this kind of sheet is distinguished from a plain copy paper by marking the sheet. However, this kind of sheet has the following drawbacks:
(a) This surface-treated image-bearing sheet is a special paper, so that it is not easy to apply this sheet to the commonly used copying machines and printers. PA1 (b) Therefore, it is difficult to mix this surface-treated papers and plain copy papers and use them in the same copying machine. PA1 (c) In view of the significance of recycling resources, duplex copies which bear images on both sides thereof are useful and will become very popular in the future. Under such circumstances, however, the method for recycling copy papers by applying a releasing agent to one side of a copy paper is neither effective nor useful. PA1 (d) Since a releasing agent is applied to a support sheet, the image fixing performance thereof is poor as a matter of course.
(2) Japanese Laid-Open Patent Applications 1-101576 and 1-101577:
A toner-image-bearing copy paper is immersed into an organic solvent in which a resin contained in the toner images formed on the copy paper is soluble, and is then subjected to an ultrasonic wave treatment, thereby removing toner images from the copy paper. This method, however, has the shortcomings that organic solvents used cause air pollution problems and are ignitable and toxic, accordingly not suitable for office or home use.
(3) Japanese Laid-Open Patent Application 1-297294:
In this application, plastics, metals, papers into which liquids hardly penetrate, and ceramics are employed as the support materials for a toner-image-bearing member. Toner images formed on the support are heated through a thermofusible releasing member, whereby toner images are peeled from the support and the support is cleaned. In this method, however, a special erasable paper subjected to releasing treatment has to be used. Therefore, this method has the shortcoming that it cannot be applied to a large quantity of copy paper and printing paper now in general use.
Furthermore, the applicants of the present invention have proposed a method for recycling the image-bearing member comprising a support material, at least part of the support material comprising a paper layer which bears images formed by a thermofusible or heat-softening ink comprising a coloring component. This recycling method comprises the steps of bringing the image bearing side of the image-bearing member into contact with an aqueous solution of at least one component selected from the group consisting of a surfactant and a water-soluble polymer; and causing an image release member to adhere to the paper layer with the application of heat and/or pressure thereto; and peeling the images away from the paper layer.
The above-mentioned image-bearing member can be recycled and again subjected to copying and printing operations, with high quality of the material being maintained. However, the thermofusible or heat-softening ink used for the image formation may contain a coloring component such as a water-soluble dye. In this case, such a dye coloring component tends to permeate through the support material and dye the same in the course of the peeling process, thereby forming residual dye images in the support material. The value of the image-bearing member as an article of commerce is impaired once dyed with the dye coloring component.